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PMC for beginners


#1

Hi, I bought a couple of sacks of PMC+. They come without
instructions, so I am not sure how to start. How can I prevent drying
out and cracks? It is possible to solder PMC+? Is it possible to set
stones in PMC material in the usual way? Tim McCreight wrote a book
on PMC, but it doesn’t seem to be extremely good. Any tips would be
welcome. Best regards, Will (Noel: thank you :-)).


#2

I can really relate to your feeling a little lost in this material.
I have been a working jeweler and teacher for many years and it took
a while for me to understand how to handle it. I now really enjoy
working with it and incorporating it in my work. It is NOT the “end
all – be all” in jewelry making techniques. It will not replace
traditional techniques of fabrication or casting. But it will do
things neither of those will do and can expand the possibilities in
jewelry making.

Here are several tips that I can give you to start:

  1. When you are working with the clay, work on a surface that the
    clay will easily lift off. I use a Teflon baking sheet and it works
    very well without any treatment. Other plastic sheets may need a
    LIGHT coating of Pam spray to help the clay release.

2.Keep a small spray bottle of water and some baby wipes nearby when
you are working. If the clay starts to show cracks, lightly mist it
with the water and roll it to mix the water in. You can put the clay
in plastic wrap to mix it if you want to keep it off your hands. I
keep my “clay in waiting” on my bench, wrapped first in the plastic
wrapper it comes in with a baby wipe wrapped around it. Whenever the
baby wipe gets a little dry, I spray it with my water bottle to keep
it wet. This keeps my clay in good shape until I can get to it. This
is not for long term storage, only for working time storage.

  1. There are a multitude of things you can do with the clay. It can
    be put in a mold (be sure it will release), or approach it like you
    would working in porcelain. You can roll it into a slab and texture,
    cut, form, fold, etc. You can pinch it or make it into a coil. You
    can make part, let it dry, work on it later. Once completely dry, it
    can be worked with burs or files. Save the dust as it can be
    reconstituted into clay again. One of the things I would highly
    recommend is to play in it. It is a VERY forgiving medium. The clay
    can be reconstituted even if it becomes completely hard. Just grind
    it up and very little water while mixing with a small pallet knife.

  2. Keep in mind that your clay will shrink. The amount of shrinkage
    depends on the clay you purchased. You can use this to your
    advantage in certain situations, but you do need to allow in your
    design for it to happen.

  3. The piece can be added to or reworked after drying. It can also
    be added to after firing and can be re-fired multiple times.

As far as stone setting, Many stones will go through the firing
process if you fire in a kiln. They recommend 7 or above on the Mohs
hardness scale, but you also have to consider inclusions or fractures
in the stone and whether or not it has been heat treated or dyed.
Diamonds do NOT work to fire in place. I have had good success with
garnet and of course with the synthetics. Any stone I plan to use in
the clay, I send through a firing first by itself. That way if it
changes color or cracks, it will do it before I have a piece planned
around it. You can also make a bezel in the traditional manner and
shove it into the clay. The clay will shrink, but the bezel will not
and you can use traditional setting techniques to set your stone.

I would be happy to walk you through some other basic things if you
want to contact me off line as I am quite sure I have through bored
most of Orchid!!

Have a great time with it. It is really fun.
Deb


#3

Call Rio back and ask for the free How To booklet on PMC, PMC + and
PMC 3. It’s quite good.

Yes, you can solder all forms of PMC, once fired. Burnish first,
use a little more solder than usual because the material is more
porous.

To not get drying out and cracks:

A.  work quickly or
B.  if the clay gets dry, add water, rewrap in Seran Wrap and let it 
	sit for 10-30 minutes;
C.  tiny cracks can be filled with slip.

What do you mean by "is it possible to set stones in the usual way?"
If you mean can you solder on a bezel after the piece is fired, then
yes.

Elaine Luther
Chicago area, Illinois, USA
Metalsmith, Certified PMC Instructor
Studio 925; established 1992
@E_Luther


#4

I know the standard wisom is that you cannot fire diamoonds in PMC
but…

Last night I tries torch firing a sherry brown diamond in PMC3 and
it worked!

Is anyone else out there defying the laws of gravity. What did I do
wronG

Tony Konrath
Key West Florida 33040


#5

Tony, Congratulations on successfully co-firing a diamond into PMC3!
Rio Grande has done some testing on this subject, and we have
successfully co-fired diamond and PMC3 twice. The advantageous lower
firing temperature of PMC3 (1110 F - 1290 F) allows for this
technique. Please bear in mind that original PMC and PMC+ require
higher temperatures (up to 1650 F) which would cause a diamond to
vaporize.

Of course putting a diamond in a kiln is always subject to some
peril. You never expect it to happen to you, but controllers might
fail, the power may spike, or some other event might cause a problem.
So I strongly recommend not firing expensive or irreplaceable
diamonds in the kiln.

Best Regards,

Kevin Whitmore
Product Manager
Rio Grande


#6

To Deb,

I wasn’t the original poster of the PMC for beginners thread,
however I am a PMC beginner and really appreciate the you
have provided. Haven’t yet taken the plunge and opened the packets
(!!), but feel a lot more confident now - thanks.

Would you mind if I also contact you offline?

Kind regards,
Marianne.


#7

Both Tim’a and MaryAnn Devos book are quite good for beginning.
Puruse the whole book quickly first for tool ideas and vocabulary.
Then go back and start the exercises in spirit if not exactly.